APPENDIX 9A Ecological Survey Results Highways Department Agreement No. CE 39/2001 Shenzhen Western Corridor - Investigation and Planning Ecological Survey Results September 2002 Ove Arup & Partners Hong Kong Ltd Level 5, Festival Walk, 80 Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong Tel +852 2528 3031 Fax +852 2268 3955 www.arup.com Job number 23306 Agreement No. CE 39/2001 Shenzhen Western Corridor - Investigation and Planning Ecological Survey Results CONTENTS Page 1. INTRODUCTION 1 2. FLORA AND FAUNA STUDY METHODS 3 2.1 Introduction 3 2.2 Habitats 3 2.3 Vegetation 3 2.4 Avifauna 4 2.5 Non-avian Terrestrial Fauna 6 2.6 Freshwater Fauna 6 2.7 Intertidal Fauna 6 2.8 Marine Fauna 7 3. RESULTS 9 3.1 Introduction 9 3.2 Uplands 9 3.3 Lowlands 10 3.4 Intertidal Zone 16 3.5 Marine Fauna 26 4. DISCUSSION 29 5. REFERENCES 30 P:\882000027\WEB PAGE\APPENDIX 9A.DOC Page i Ove Arup & Partners Hong Kong Ltd 23306-REP-057-03 September 2002 Agreement No. CE 39/2001 Shenzhen Western Corridor - Investigation and Planning Ecological Survey Results TABLES Table 3.1 Bird density and species richness in upland habitats (mean ± standard error) Table 3.2 Bird density and species richness in fishponds (mean ± standard error) Table 3.3 Total numbers of nesting birds at Pak Nai and Ngau Hom Shek egretries Table 3.4 Relative importance (%) of nesting populations at Pak Nai and Ngau Hom Shek egretries in Deep Bay area and Hong Kong Table 3.5 Percentage use of each type of foraging habitat for Little Egrets flying from Pak Nai egretry in May 2002. Table 3.6 Percentage use of foraging habitat for Little Egrets and Chinese Pond Herons flying from Ngau Hom Shek egretry in May 2002. Table 3.7 Summary of flight-line studies of Pak Nai and Ngau Hom Shek egretries Table 3.8 Dragonfly and butterfly species richness. Table 3.9 Mean Bird abundance and species richness in inter-tidal mudflats (mean ± standard error) Table 3.10 Mean Bird abundance and species richness in inter-tidal mudflats after oyster beds were created at Ngau Hom Shek (mean ± standard error) Table 3.11 Bird density and species richness in tidelines (mean ± standard error) Table 3.12 Bird density and species richness in mangroves (mean ± standard error) Table 3.13 Numbers of Black-faced Spoonbills in the study area Table 3.14 Table of statistics of the intertidal infauna samples. Table 3.15 List of benthic infauna recorded in the mudflat infauna samples. Table 3.16 Results of epifauna survey on mudflats. Table 3.17 Results of epifauna survey in mangroves. Table 3.18 Results of Epifauna survey on seagrass beds. Table 3.19 Species list of infauna found in the subtidal grab samples Table 3.20 Table showing the mean values of number of species, S; species diversity, H’ (Shannon Wiener’s Index); and species evenness, J for the 6 sites of dry and wet seasons in the subtidal infaunal survey. CHARTS Char 3.1 Total numbers of nesting birds at Pak Nai (circle) and Ngau Hom Shek egretries (square) Chart 3.2 Frequency of Flight Heights During Low Tide Chart 3.3 Frequency of Flight Heights During High Tide Chart 3.4 Cumulative percentage of recorded flight heights at 3 m altitude intervals above the mudflat during high tides and low tide ANNEX TO APPENDIX 9A Annex A to AC P:\882000027\WEB PAGE\APPENDIX 9A.DOC Page ii Ove Arup & Partners Hong Kong Ltd 23306-REP-057-03 September 2002 Agreement No. CE 39/2001 Shenzhen Western Corridor - Investigation and Planning Ecological Survey Results 1. INTRODUCTION 1.1.1 The objective of this report is to present results of flora and fauna surveys carried out from 20 August 2001 through 13 June 2002. Results presented here cover the “wet season”, which is normally considered to be the annual 7-month period from April through October (AFCD-EPD 2001), and the “dry season” (5-month period from November to March) (ibid.). The contract for the consultancy was signed on 21 August 2001, which precluded field survey of flora and fauna during the early months of the 2001 wet season. For this reason field surveys were commenced at the latter part of the wet season in 2001, and covered the 2001-2002 dry season, and also the early part of the wet season in 2002. 1.1.2 This report is presented in five sections. The introduction is followed by Section 2, a description of study methods. Section 3 lists results and presents analyses of field works. Section 4 is a discussion and interpretation of the survey results. Section 5 lists references cited in this paper. 1.1.3 This report summarises and provides cumulative data and results of the field surveys performed for the current study. References that are relevant to study methods or results are cited and listed in this report, but not all documents relevant to the overall study are cited or reviewed herein. Comprehensive review is presented in Section 9 of the main report. 1.1.4 According to section 3.4.5 of the Study Brief ecology studies should accomplish the following: “establish a comprehensive ecological profile of the study area based on data of previous studies and results of additional field surveys, and taking into consideration the variations across four seasons, and describe the characteristics of each habitat found; major information to be provided shall include: (1) description of the physical environment; (2) habitat maps of suitable scale showing the types and locations of habitats in the study area; (3) ecological characteristics of each habitat type such as size, species present, dominant species found, species diversity and abundance, community structure, seasonality, inter- dependence of the habitats and species, and presence of any features of ecological importance; (4) representative colour photographs of each habitat type and any important ecological features identified. 1.1.5 The Study Brief directs that the flora and fauna surveys should: “investigate and describe the existing wildlife uses of the various habitats with special attention to those wildlife groups and habitats with conservation interests, including but not limited to the following: (1) inter-tidal mudflat (2) mangrove (3) seagrass bed (4) avifauna, in particular, Black-faced Spoonbill (Platalea minor) (5) egretries (6) inter-tidal and sub-tidal benthic faunal communities (7) Chinese White Dolphin (Sousa chinensis) (8) Horseshoe crabs (9) any other habitats and wildlife groups identified as having special conservation interests by this EIA study.” 1.1.6 The programme of flora and fauna field study reported here has been designed to meet the above listed Study Brief requirements. P:\882000027\WEB PAGE\APPENDIX 9A.DOC Page 1 Ove Arup & Partners Hong Kong Ltd 23306-REP-057-03 September 2002 Agreement No. CE 39/2001 Shenzhen Western Corridor - Investigation and Planning Ecological Survey Results 1.1.7 There is confusion in Hong Kong over application of the terms “wet season” and “dry season” to field study of wild flora and fauna. This confusion results from earlier (late 1980s through late 1990s) disregard in impact assessment studies for seasonality in various ecological or biological processes. Examples can be seen in studies where, for example, amphibian surveys were carried out in winter (when amphibians are difficult to see or hear), with the result that amphibian species representation and numbers were under-reported. This can be corrected by sampling in April-May, when amphibians can be seen and heard. Similarly, late summer surveys of birds resulted in under-reporting of passage migrants and winter residents. This can be corrected by sampling birds in September-October (for autumn migrants), January (for winter residents), April-May (for spring migrants), and May-June for summer residents and local breeders. In both of these examples the correct sampling regime would be missed by strict adherence to “wet season” and/or “dry season” surveys. In both cases application of professional judgment and local experience is required to specify the appropriate sampling regime. 1.1.8 Section 3.4.5.4 of the Study Brief directs in paragraph (i) that related studies should be reviewed, in particular the Feasibility Study for Additional Cross-border Links Stage 2 (Mouchel 2000, hereafter referred to as “Crosslinks2”), and the current Deep Bay Link study (Ove Arup, in process). Paragraph (ii) directs that reviewed information be analysed to identify data gaps relevant to this study, and a determination made “whether another full-year seasonal ecological survey shall be required to bridge any information gap or update the information to ensure that a comprehensive ecological profile can be established as required...”. Paragraph (iii) directs that surveys deemed necessary to fill data gaps or update information be carried out, “the duration of which shall be at least 6 months and cover both the wet and dry seasons”. 1.1.9 As noted in paragraph 1.1.7 above, sampling over 6 months to cover the wet and dry seasons is inappropriate for amphibians because it implies survey in the dry season when the resulting data would be largely useless: Breeding season surveys at the onset of the wet season are appropriate for amphibians. Similarly, 6 months of survey over wet and dry seasons for birds would yield useless data if surveys were not scheduled to coincide with the periods of ecological significance for birds in Hong Kong (see paragraph 1.1.7). When both migratory and resident birds are a concern, as they are in this study, 6 months of survey will generally be inadequate. This relationship between survey timing and effort is referenced in the TM Annex 16, Section 5.1.4.